There exists a wide variety of applications in which it is desirable to measure and/or monitor to some degree certain ambient conditions within a container or the like, such as the level of a fluid, the flow rate of a fluid, the turbidity of a fluid, the temperature of a fluid or its surrounding environment and the ambient pressure. Such applications may range from monitoring these conditions in various systems, such as an internal combustion engine or fuel tank, a pump or compressor, or even within a tank or tub, such as for a household appliance like a dishwasher or clothes washer.
In each of these applications it is desirable that the multi-function sensor be capable of providing a reliable, accurate indication of the fluid level, fluid flow rate, turbidity, temperature and/or pressure over an extended period of time without requiring periodic maintenance. In many applications the sensor must be capable of enduring various degrees of vibration, heat or other hostile environmental elements, as well as space limitations. Additionally, in some applications utilizing sealed vessels such as hermetic compressors and household appliances, it is desirable to minimize the number of penetrations through the wall(s) of the vessel in order to reduce the potential for leakage.
Various types of devices have been developed over the years for separately sensing individual conditions such as fluid level, fluid flow rate, fluid turbidity, fluid and/or ambient temperature, and fluid and/or ambient pressure. Such sensor devices, however, have not combined the multiple functionalities into a single sensor device.